An alpine touring binding (also known as an AT binding or randonnée binding) is a specialised ski binding

Ski binding

A ski binding is an attachment which anchors a ski boot to the ski. There are different types of bindings for different types of skiing.-Universal designs:...

 with a releaseable locked down heel that can be used for ski touring

Ski touring

Ski touring is a form of backcountry skiing involving traveling over the winter landscape on skis under human power rather than through the assistance of ski lifts or snow vehicles. It can take place in terrain ranging from perfectly flat to extremely steep...

 and backcountry skiing

Backcountry skiing

Backcountry skiing is skiing in a sparsely inhabited rural region over ungroomed and unmarked slopes or pistes, including skiing in unmarked or unpatrolled areas either within the ski resort's boundaries or in the backcountry, frequently amongst trees , usually in pursuit of fresh fallen powder...

. Most AT bindings have DIN safety release as in an alpine binding. Specialized alpine touring ski boot

Ski boot

Ski boots are specialized footwear that are used in skiing to provide a way to attach the skier to skis using ski bindings. This ski-boot-binding combination is used to effectively transmit control inputs from the skier to the snow....

s are also used, something of a cross between a downhill ski boot and a plastic climbing boot, which are light and flexible enough to be comfortable to walk up in while still being stiff enough to provide good control when skiing down. These boots have soles with traction and the ability to hold a crampon when climbing steep slopes with the skis carried on one's backpack

Backpack

A backpack is, in its simplest form, a cloth sack carried on one's back and secured with two straps that go over the shoulders, but there can be exceptions...

.

Use

During ascent, the skis are fitted with self-adhesive plush climbing skins to prevent them from slipping backwards. The ski binding heels are released to allow a Nordic style of striding. The skins are very effective in preventing the skis slipping backwards, much more so than grip wax

Ski wax

Ski wax is a material applied to the bottom of skis or snowboards to improve the ski's performance on snow. It can also be applied to other devices that slide over snow and ice such as toboggans.- Types of ski wax :...

, and quite a steep hill can be ascended directly without resorting to side stepping or herringboning. The heels of the bindings are often fitted with adjustable steps to maintain the soles of the boots horizontal on a steep climb. Prior to descent, the skins are removed, the heel steps removed or lowered, and the binding heel piece is locked down. Descent is then by conventional alpine skiing

Alpine skiing

Alpine skiing is the sport of sliding down snow-covered hills on skis with fixed-heel bindings. Alpine skiing can be contrasted with skiing using free-heel bindings: Ski mountaineering and nordic skiing – such as cross-country; ski jumping; and Telemark. In competitive alpine skiing races four...

 technique.

Compared to Nordic boots and bindings, the alpine touring binding is less suitable for undulating terrain, but is more versatile on steeper and more difficult snow. Like telemark skiing

Telemark skiing

Telemark skiing is a form of skiing using the Telemark turn. Unlike alpine skiing equipment, the skis used for telemarking either have a binding that only connects the boot to the ski at the toes, just as in cross-country skiing, or may be released to only connect there.Telemark turns are led with...

 gear, this equipment is popular with people from an alpine skiing

Alpine skiing

Alpine skiing is the sport of sliding down snow-covered hills on skis with fixed-heel bindings. Alpine skiing can be contrasted with skiing using free-heel bindings: Ski mountaineering and nordic skiing – such as cross-country; ski jumping; and Telemark. In competitive alpine skiing races four...

background; but unlike telemarking, it requires no learning of a new type of downhill turn. Because the fixed heel provides additional support and lessens the force on the toe hinge in downhill mode, modern AT gear and telemark gear are comparable in weight, with both sacrificing control on the descent to reduce weight.

Manufacturers

The main manufacturers of AT bindings are Silvretta, Fritschi Diamir, Marker and Dynafit. Backcountry Access also produces a binding adapter to allow downhill alpine skis and bindings to undertake limited touring.